Plunger construction for solenoid hammers



April -8 1924.

F. DAVEY PLUNGER CONSTRUCTION FOR SOLENOID HAMMERS Filed Jin. 5; 1921 [fl'i'nesses Patented Apr. 8, 1924.

UNITED STATES PATENT OFFICE.

PLUNGER CONSTRUCTION FOR SOLENOID HAMMERS.

Application filed January 5, 1921.

T all whom it may concern.

Be it known that I, FREDERICK W. DAVEY, a citizen of the United States, residing in Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Plunger Constructions for Solenoid Hammers, of which the following is a specification.

This invention relates to electric hammers of the type in which the hammer or plunger member is reciprocated by means of electric solenoids which are alternately energized for drawing the reciprocating member back and forth. The invention relates more particularly to an improved plunger suitable for use in the electric hammer described in my co-pending application, Serial No. 324,755, filed October 27, 1920, patented May 10, 1921, No. 1,377,562.

Objects of the invention are to provide an eflicient construction for the reciprocating plunger or hammer member, and to provide efficient means for insulating the plunger or hammer member during the operation thereof.

Another object is to provide an arrange ment whereby insulating bushing of the reciprocating member will be prevented from becoming displaced.

Other objects of the invention are to provide an efiicient arrangement for insulating the contact plates and other connections from the reciprocating hammer member, and to provide suitable contacts for moving the hammer member.

Still another object is to provide a strong, durable, and easily manufactured recipro eating member of the above kind.

Other objects of the invention will appear as the description proceeds; and while herein minute details of the invention are described, the invention it not limited to these, since many and various changes may be made without departing from the scope of the invention as claimed.

In the accompanying drawing, showing by way of exam le, one of many possible embodiments of tlie invention,

Figure 1 is a fragmental central longitudinal sectional view showing part of I the operating and controllingmechanisms of the hammer of said application, and the reciprocating plunger with part of the insulation cut away.

Serial No. 435,262.

Figure 2 is a side elevation partly in central longitudinal section showing the plunger and contacts; and

Figures 3 and 4 are sectional views taken on the lines 3-3 and M, respectively, of Fig. 2.

Figure 5, is a side elevation showing the plunger and contacts, the plunger being in a position at right angles to the position of the plunger in Fig. 2.

As fully shown and described in said patent the hammer is provided with an axial guide tube having an interior square in cross-section, which interior is conformably lined with insulating material 10, within which tube, between a rear buffer, not hereshown, and the tool spindle 11, there is slidably disposed areciprocating member or plunger. The invention herein relates to the construction of this plunger herein designated by reference character 12. This slidable reciprocatory plunger 12 has a re duced striking end 14 adapted to strike the tool spindle 11 and comprises a body portion 15 of square cross-section consisting of soft iron or other suitable magnetic con ducting material provided with wide transverse contact receiving recesses 16, disconnected under-cup grooves 18 and transverse front and rear openings 19 disposed in staggered angular relation and passing through the plunger and the axis thereof and disposed a distance apart about equal to the length of the stroke of the plunger and registering with said transverse recesses 16.

An insulating bushing 20 covers the side faces of said body portion and said plunger from end to end, and is provided with interior under-cut ribs 22 dove-tailing with said undercut grooves. Said bushing is also provided with large openings 23 alined with the ends of said transverse openings 19 and registering with the transverse recesses 16. Insulating material 25 completely lines said recesses and transverse openings.

Pairs of contact plates-26 disposed in said transverse recesses 16 are embedded in said insulating material and provided with under-cut outer contact faces disposed within and engaging on the edges of said large openings 23 of the bushing. Front and rear rivets 27 and 28 are embedded in said material 25 and pass through said transverse openings and said contacts and electrically IOI and mechanically connect the contact plates 26 of each pair with each other.

As shown in the before mentioned patent, two pairs of carbon brushes 30 (Fig. 1) are adapted to engage said contact plates 26, and these brushes are so arranged and connected to solenoids 31 and 32 that the operation of the device causes the current to energize the rear solenoid 31 whereupon the plunger 15 is drawn to its rearmost position, and the forward rivet 27 is brought into contact with the brushes so that the current passes through the forward solenoid 32, thus energizing the forward solenoid and carrying the plunger forward to strike the tool spindle 11 to operate the tool. This operation is then continued so long as current is applied.

I claim as my invention:

1. In combination, a plunger; insulating material around the plunger on all of its sides connected thereto and extending lengthwise thereof; contact means arranged on opposite sides of the plunger and insulated therefrom; and conducting means passing through the plunger insulated therefrom and connecting the contact means.

2. In combination, a plunger; insulating material around the plunger on all of its sides connected thereto and extending lengthwise thereof; contact means arranged in opposed relation on sides of the plunger forwardly and insulated therefrom; contact means arranged in opposed relation on sides of the plunger rearwardly and insulated therefrom; the forwardly arranged contact means being in a plane at right angle to the plane of the rearwardly arranged contact means; and conducting means passing through the plunger and insulated therefrom and connecting the oppositely related contact means.

3. In combination, a reciprocatory plunger; an insulating busing covering said plunger; pairs of oppositely disposed con-' ducting plates embedded in said bushing and insulated from the plunger; and forward and rear conducting rivets passing transversely through and insulated from said plunger and arranged in staggered relation to each other and electrically and mechanically connecting said plates of the same pair.

l. In combination, a slidable reciprocatory plunger having a body portion of square cross-section consisting of soft iron or other suitable magnetic conducting material provided with wide transverse recesses, undercut disconnected grooves, and transverse front and rear openings, the latter passing entirely through the plunger and the axis thereof and disposed a distance apart about equal to the length of the stroke of the plunger and registering with said transverse recesses; an insulating bushing covering the side faces of said body portion of said plunger from end to end and provided with interior under-cut ribs dove-tailing with said under-cut grooves, said bushing being also provided with large openings registering with the ends of said transverse open ings and with the transverse recesses; insulating material completely lining said recesses and transverse openings; contact plates disposed in said transverse recesses and embedded in said insulating material and provided with undercut outer contact aces disposed within and engaging over the edges of said large openings; and front and rear rivets embedded in said material and passing through said transverse openings and said contacts and electrically and mechanically connecting the contacts of each pair with each other.

5. In combination, a plunger having grooves; an insulating bushing covering said plunger and having ribs engaging said grooves; and conducting rivets passing transversely through said bushing.

6. In combination, a plunger; an insulating bushing covering said plunger and having dove-tailed connection therewith; and conducting rivets passing transversely through said bushing.

7. In combination, a slidable reciprocatory plunger provided with transverse undercut portions; an insulating bushing cove-ring said plunger and provided with under-cut parts engaging under said portions of the plunger; and conducting rivets passing transversely through said plunger and bushing and insulated from said plunger.

8. In combination, a slidable reciprocatory plunger having a body portion of square cross'section and consisting of soft iron or other suitable magnetic conducting material provided with disconnected transverse under-cut grooves; a bushing of insulating material covering the side faces of said body portion of said plunger from end to end and provided with interior under-cut ribs dove-tailing with said under-cut grooves, and forward and rear conducting rivets passing transversely through said bushing and plunger and insulated from said plunger and arranged in staggered relation to each other.

9. In combination, a plunger; an insulat ing bushing covering said plunger; forward and rear conducting rivets passing transversely through said bushing and insulated from said plunger; and conducting plates arranged on the ends of said rivets.

10. In combination, a reciprocatory plunger of magnetic conducting material; an insulating bushing covering said plunger; pairs of oppositely disposed conducting plates embedded in said bushing and insulated from the plunger; and forward and rear conducting rivets passing transversely through said plates and plunger and insulated from said plunger and arranged in sta gered relation to each other and electri- 09.1% and mechanically connecting said plates of the same pair.

11. In combination, a slidable reciprocatory plunger having a body portion of square cross-section consisting of magnetic conducting material provided with wide disconnected transverse recesses and transverse front and rear openings passing entirely through the plunger and registering with said transverse recesses; an insulating bushing covering the side faces of said body portion and provided with large openings registering with the ends of said transverse openings and with the transverse recesses; insulating material completely lining said recesses and transverse openings; pairs of contact plates dis sed in said transverse recesses and embe ded in said insulating material and provided with under-cut outer contact faces disposed within and engaging over the edges of said large openings; and front and rear rivets embedded in said material and passing through said transverse openings, said insulating material and said contacts and electrically and mechanically connecting the contacts of each pair with each other.

12. In combination, a plunger having transverse recesses in opposite faces, and transverse front and rear openings passing entirely through the plunger and the axis thereof and disposed a distance apart about equal to the length of the stroke of the plunger, and registering with said transverse recesses; an insulating bushing covering said plunger with large openings registering with the ends of said transverse opening and with the transverse recesses; insulatin material completely lining said recesses and transverse openings; contact plates disposed in said transverse recesses embedded in said insulating material; and rivets embedded in said insulating material and passing through said transverse openings and electrically connecting the contacts of each pair with each other.

FREDERICK WV. DAVEY.

Witnesses:

H. M. KILPATRIOK. H. D. Pnmmr. 

